1. Field of the Invention
The present invention relates to a method for booting a personal digital assistant (PDA), and more particularly, to a method for booting a PDA using an external memory card.
2. Description of the Related Art
In general, the PDA is a multi-media product having several functions such as a cellular phone, wireless facsimile, a radio pager, and an electronic pocketbook. It is possible for the PDA to transfer information to a host computer and receive information from the host computer, regardless of time and place, by using a portable information terminal. It is also possible to search and receive the information from a data base which is connected to the computer.
When development of an operation program for the PDA is completed, the PDA records the program on an internal read only memory (ROM) to perform various functions. However, a ROM presently in the PDA must be replaced by a new ROM when the contents of the ROM are to be renewed.
Additionally, the conventional PDA includes a switch for controlling a start-up code. The switch is connected to two I/O ports and is controlled to be in the on and off states. If a reset button is pressed with the condition that the switch has also been pressed, a microprocessor executes a start-up command depending on whether the I/O ports are turned on or off. For example, if the two ports are switched on, a DEMON program, corresponding to a debugger program of the host computer, is executed. Otherwise, a default application program is executed.
FIG. 1 is a flowchart showing a method of executing the start-up command in a conventional PDA. In step 210, a desired start-up command is selected using a switch. In step 220, the start-up commands inside the ROM are executed by booting the PDA. In step 230, a desired job is performed according to the start-up command. Therefore, a second deficiency of the conventional PDA is that a s hardware switch is required in order to execute one of several start-up commands. Accordingly, assembly work for producing the PDA increases.